The Wind Wing Electric Generator was developed as a means of converting mechanical energy into electrical energy for an invention named the Wind Wing (application Ser. No. 13/716,465 filed Dec. 17, 2012). Upon advice from the USPTO the application was divided Oct. 10, 2013. Three of its original six claims which were withdrawn from it and, following editing, have been traversed to this application. Beyond this role, the Wind Wing Electric Generator has broader application than simply as a mechanical energy to electrical energy conversion system for a Wind Wing.
The Wind Wing was conceived as means of converting wind energy into electrical energy with minimal displacement of mass.
It was belief of the inventor that a vertical unarticulated airfoil, capable of rotating to a limited but significant degree around a vertical shaft, could be engineered to oscillate in the wind. And that following Faraday's Law of Induction, a coil attached to the airfoil's trailing edge, nearby a pole of a stationary magnet, would have a voltage induced within it. That wind energy might be converted into electrical energy with such minimal movement of mass suggested it might produce a simpler, more reliable, safer, and less expensive alternative to existing methods of converting wind energy into electrical energy.
A small wind generation machine was constructed using a variable speed DC (automobile radiator) fan, and a range of unarticulated airfoils were fabricated and tested. None was able to achieve oscillation.
The problem is that, as an unarticulated airfoil rotates, lift decreases in the direction its tail rotates; while at the same time it increases in the reverse direction. With sufficient airflow, most unarticulated airfoils will flutter or vibrate. But they will not oscillate across any significant angular range.
This testing did reveal however, that when an unarticulated streamlined symmetrical airfoil was mounted vertically inside an open-ended box structure through which passed a 5 MPH+ (2.235 M/S+) airflow, the forces keeping its chord parallel to the airflow (named the “Restoring Forces”) were much stronger than anticipated. This led to three principal concurrent research and development efforts.
The first was to survey and exercise of a range of web accessible computational fluid dynamics programs (NASA FoilSim, JavaFoil, etc.) to determine what kinds of airfoils in what configurations would yield the very low static pressure that appeared responsible for these Restoring Forces. After literally hundreds of test runs, it became apparent that by carefully selecting, sizing and positioning three vertical streamlined symmetrical unarticulated airfoils, the outside two each having a cross section close to NACA 0020, and the middle one having a cross section close to NACA 0040, air velocity in sections of the channels between them would be increased, and static pressures decreased, to shocking degrees.
The second was the development of a simple scheme for taking advantage of these very low pressure sections of the channels to convert wind energy into mechanical energy: Keeping the apparatus face to the wind, segmenting the cross section of the middle streamlined symmetrical unarticulated airfoil (the one having a cross section close to NACA 0040) into the cross section of a Forward Nacelle, the cross section of an Aft Nacelle, and copying the remaining cross section, rotating the copy around the axis of a shaft approximately 53 degrees, and uniting the copy and the original, creating the cross section of a new airfoil which would, in the presence of sufficient airflow, oscillate over a range of almost 60 degrees. This new airfoil was named the “Oscillating Wing.”
Testing of models incorporating these developments on the top of the inventor's car revealed a number of advantages over turbines. The first is the Wind Wing's inherent structural stability. Some of this is due to the structure itself, four vertical members (Two outside walls [a Starboard Wall and a Port Wall], a Forward Nacelle and an Aft Nacelle) all anchored at each end in a Roof and Floor (the Oscillating Wing pivoting in bearings in the Roof and the Floor). Part of it is due to the Wind Wing's use of the monocoque construction technique—introduced by the French in their WW I airplanes and employed by the airplane building industry ever since. At one point an early Wind Wing model, constructed of some wooden dowels, foamboard, glue and paper, literally blew off from the top of the inventor's car and bounced along the abandoned runway which the car was being driven up and down. It was recovered without damage. The same model was then able to withstand, and function in 50+MPH (22.352+m/s) of apparent wind—meaning it will likely not require the furling capability demanded by all but the smallest of turbines. Most rewardingly, videos of its performance showed a remarkable pattern of oscillations, increasing in frequency with increasing apparent wind speed, but asymptoting at approximately 10 CPS in approximately 35 MPH (15.646 m/s) of apparent wind. Together, they indicate good size (roughly 10 foot [3 Meter] high) Wing Wings could be deployed in highly urban environments without most of the significant dangers to humans and flying creatures (to say nothing of unsightly appearance) associated with turbines of the same or larger size.
The third principal research and development effort was toward inventing what became the Wind Wing Electric Generator. The originally conceived concept had two elements: a coil wrapped around the Oscillating Wing (hereafter, the “Coil”), and a magnet positioned aft of, and nearby it. Both of these elements went through a series of improvements, often on the basis of observations concerning the states of related arts, and sometimes using techniques that had been for the most part abandoned. The result is a machine which relatively efficiently converts oscillating rotating mechanical energy of a limited range (roughly 60 degrees) into electrical energy. And which more importantly, appears can be fabricated at very low cost by local craftspeople using mostly locally available materials in almost any community anywhere in the world.
The first step in advancing the Coil involved discovering a geometry of wrapping it which would allow positioning of magnets both fore and aft of its aft side. This theoretically should allow flux density across the aft side of the Coil to be doubled from what would be the case were it limited to the same magnet(s) on only one side—thereby doubling the voltage induced in the Coil as its aft side oscillates between them. To enable this, the Coil has to be wrapped in a unique manner with alternative wrappings clearing each side of whatever is used to support the magnet(s) forward of the aft side of the Coil when the Oscillating Wing is rotated through its entire 60 degree range—as well as keeping the Coil's moment as low as practical so as to minimize the effect on the Oscillating Wing's ability to oscillate. The final solution appears unique and constitutes one of the claims of this application.
As it became increasingly apparent that in many of the poorer communities of the in the world, capable Wind Wings (with sufficient local wind [estimated to be available at any time in 30% of the inhabited world] should be able to illuminate two small rooms [using LEDs], power a smart phone, etc.) might fabricated by local craftsman using locally available materials, focus was directed on the cost of Coil wire, particularly with the most obvious material, copper, currently experiencing historic cost increases.
Over the next few months it was recognized that aluminum is likely to prove a better alternative: Because it is almost freely available in discarded soft drink cans, has a relatively low melting point, relatively high conductivity, is relatively light in weight, and properly annealed, becomes relatively malleable. Furthermore, the methodology of drawing wire has been in existence since the Middle Ages. All that appears would be to fabricated it are (not inconsiderable) know-how, blacksmithing capabilities, and of course, source materials such as aluminum cans and a lubricant (to facilitate wire drawing). Final preparation would involve coating the wire with a locally concocted resin to change it into magnet wire.
So that it appears that with adequate instruction, based in significant part upon study of local situations, it should be possible to for local craftsmen to draw sufficient wire for a small to medium size (3-4 feet [0.9 to 1.2 meters] high) Wind Wing with approximately one or two man-days of labor per. In poorer communities of the world, this cost might not be much more than $7. Finally, automated wire drawing machinery is available at affordable cost to NGO and governments wishing to support regional efforts.
Appearing even more inspired was the series of discoveries that drove the evolution of the assembly that positions magnets fore and aft of the aft side of the coil, here named the Dipole Permanent Magnet Assembly (abbreviated as the “PDMA”). It is a remarkable unit.
A DPMA is built up from two identical L-shaped iron bars, one rotated 180 degrees from the other, so that when brought together with the ends of the shorter sections of the Ls positioned flush against the insides of the longer sides of the other bars, they form a rectangle. Among the remarkable things discovered about this rectangle is that by hammering the length of the shorter side of these L-shaped bars, the longer sides can be brought closer together in 1/10,000-inch (0.00025-meter) increments. This means that using them to house magnets fore and aft of the aft side the Coil, the gap between these magnets (through which the aft side of the Coil oscillates) can be adjusted to be no wider than absolutely necessary to allow the aft side of the coil to oscillate through it. This precision rivals machine tooling toward the same objective.
Cut into, or punched into (by blacksmithing) into the longer sides of these L-shaped bars can be slots through which multiple individual magnets, with their poles all aligned in the same fore and aft direction, can be wedged after being inserted from the bars' outsides. Because of this housing capability these L-shaped bars have been named the “Forward Magnet Array Holder” and the “Aft Magnet Array Holder.”
It can be appreciated that each is no more complicated (although somewhat larger) than a horseshoe. They are thus capable of being fabricated by a reasonably capable blacksmith with not much more than ½ hour of effort each.
Two other L-shaped bars, named “Backing Plates” can then fit over the outsides of the Forward Magnet Array Holder and the Aft Magnet Array Holder and, being secured with something as simple as twine, insure that the magnets remain in their slots (but allowing them to be conveniently replaced when justified)—and most remarkably provide a least-resistance path for flux between the outside poles of the magnets housed in the Forward Magnet Array Holder and those housed the Aft Magnet Array Holder—this path going over and under the aft side of the Coil.
This least-resistance (iron) path essentially eliminates what would otherwise be a (air) path (from the forward pole(s) of the forward array of magnets to the aft pole(s) of the aft array of magnets) through the aft side of the Coil. It thus provides the critical element in using magnets on both sides of the aft side of the Coil.
The horizontal outline of each magnet is logically an isosceles trapezoid (allowing them to be wedged into the slots in the Forward Magnet Array Holder and those the Aft Magnet Array Holder, where they can be held in place by the Backing Plates). When these magnets are stacked vertically and congruently, and held together, they form what are known as compound magnets.
Where a compound magnet gains its advantage over a simple bar magnet of equal total size is in their individual magnets being much more conducive whatever techniques is used to magnetize them by (being shallower) having their about-to-be-magnetized domains closer to its surfaces and thus more susceptible to the magnetizing force.
Through the late 1800s, compound magnets were the most recognized means of creating strong magnetic fields. They then fell behind improving metallurgy and stronger electro-magnetizing. Here again, beyond communities creating their own magnets and compound magnets, there are opportunities for organizations wishing to sponsor regional efforts by providing at low cost relatively powerful magnets along with Coil wire.
The total cost for both (wire and PMDA), sufficient to construct a Wind Wing Electric Generator for small to medium size (3-4 feet [0.9 to 1.2 meters] high) Wind Wing should be not much more than $14.
As it became increasingly apparent that most of a small to medium size Wind Wing could be fabricated by local craftsmen using locally available materials at low cost in almost any poor community anywhere in the world, consideration was directed toward making the design freely available to these communities building them for their own use.
The potential appeared and still appears enormous. Somewhere between 20% and 30% of the world lives without economic access to electricity. And at least 25% of them live in areas where there is sufficient wind that, with progressing LED and battery technologies, it appears possible to replace much of their use of fire (including kerosene lamps) for household illumination after the sun has set, and even to power internet access smart phone.
This potential is magnified when one considers virtually every other really significant advancement in converting wind energy into mechanical energy and mechanical energy into electrical energy occurred following initial discovery of the technology, when engineers took over from the inventor. It seems not unreasonable to anticipate that this will occur with the Wind Wing and the Wind Wing Electric Generator.
To accelerate both developments, the inventor decided to surrender all rights to poorer communities building such machines for their own use via the US Government—who could then rightfully claim further development from these machines current status, as well as handle distribution of enabling information to these communities. Aside from the humanity of such an effort, it would further its intent to affect climate change, to say nothing of enhancing its image. In this direction, correspondence was initiated with the National Renewable Energy Laboratory (“NREL”), including sending them a video of the testing conducted on the inventor's car and a 43-page write-up prepared by the inventor to insure survivorability of what had been recognized by him up through September 2012. These items remain available to responsible parties.
While this correspondence remained encouraging throughout, it eventually became apparent that, in the words of the Director of the NREL, ‘it was not within its authority to so direct its resources.” At that point it appeared prudent to apply for a US patent. And an application was filed Dec. 17, 2012 (application Ser. No. 13/716,465).
One of the items raised by the NREL Senior Engineer with whom most of the correspondence was conducted, and later in conversation by the Director, was their opinion that the next item in the inventor's agenda might be “testing with a load on the Oscillating Wing.”
Until then, and after the inventor had not seen this as a principal issue. Because, while it obvious there is some load that will delay and otherwise inhibit oscillation, the Oscillating Wing is remarkably scalable in terms of being able to capture more wind energy, converting it to more mechanical energy thus increasing its ability to function with an additional limited load on it.
Like on an airplane, (or on a turbine) where lift can be increased by extending the wings (or on a turbine, the blades), lift in a Wind Wing—and thus its ability to convert wind energy into mechanical energy—can be increased by simply extending the (vertical) length of the Oscillating Wing (and with it of course, the vertical elements that connect its Roof and Floor: its Forward Nacelle, Aft Nacelle, Starboard Wall and Port Wall).
However unlike an airplane wings (or turbine blades) which are anchored at only one end (at the fuselage, or on a turbine, at the turbine axis) the Oscillating Wing is anchored at both ends (at the Roof and at the Floor). Structurally, this makes it 4 times more resistant to bending by pressure along its length (such as exerted by the local apparent wind). Beyond this, an Oscillating Wings maintains the same cross section across their entire length. So that the machine is extraordinarily scalable. And problems resulting from an debilitating loading of an Oscillating Wing appear among the most easily to remedy.
Recent studies of another machines attempting to improve upon turbines have been encouraging. One in particular, focused on an articulated Oscillating Wing apparatus (in contrast to the Oscillating Wing in the Wind Wing being unarticulated), the Wind Fin, titled ‘Wind Energy Extraction Using a Wind Fin’ by Professors Mark Costello and Vasudevan Manivannan of Georgia Tech, capsulizes, in its Introduction, the Wind Wing's power potential: “While the geometry and operation of the wind fin is far different from horizontal axis wind turbines, the power output is within the same range.” The significance of this is that relative to horizontal axis wind turbines the Wind Wing, (including its Wind Wing Electric Generator) should cost 60-70% less, avoid a turbine's danger to humans and other creatures, prove more reliable, function over a broader range of environments and be seen as more attractive in urban settings
With the granting of patent protection, the inventor plans to make the Wind Wing and Wind Wing Electric Generator public. With the attention directed toward the Wind Fin and another innovative concept, the Windbelt, and with its potential to provide electricity to communities unable to afford it; allowing them longer days, expanding educational tools and reducing human toil, poverty, deforestation, pollution and global warming, it appears not unreasonable that it will attract sufficient improvement efforts to do real good in the world.
Finally, it appears that the Wind Wing Electric Generator is likely to find application other than in Wind Wings. There appear to be literally thousands of situations where oscillating mechanical energy is being wasted because of lack of an economical and reliable means of converting it into electrical energy. The Wind Wing Electric Generator appears capable of filling part of this void.